Snagging grinder



Oct. l1, 1960 H. v. LAVNER v SNAGGING GRINDER 6 Sheets-Sheet 1 FiledDec. 7, 1956 /lTTo/QNEY Oct. 11, 1960 H. V. LAVNER SNAGGING GRINDERFiled Dec. 7, 1956 6 Sheets-Sheet 2 Hag? l lNveNToR HELGE V LA V/VEE BYkwQhLeJ-ch.

HTTOENEX Oct.A ii, i960 H. v. LAvNr-:R 2,955,383

sNAGGING GRINDER Filed Dec. 7, 1956 6 Sheets-Sheet 5 Fig.; INVENTORHELGE VLA VNER Oct. 11, 1960 H. v. LAVNER SNAGGING GRINDER 6Sheets-Sheet 4 Filed Dec. 7, 1956 INVENTOR HELGE V LA VME/E @wwwQTTOENEY Oct. 1l, 1960 H. V, LAVNER A. 2,955,388

SNAGGING GRINDER Filed Dec. 7, 1955 6 Sheets-Sheet 5 111 III@ IIIIlllllIl-I .228

Hag. 5

I l v Z lNvENToR Hg. 6 HELGE V LAVA/ER Oct. 11, 1960 H. v. LAVNER2,955,388

SNAGGING GRINDER Filed Dec. 7, 1956 6 Sheets-Sheet 6' Ll 7 o 7/ Z55 /4Z55 l 6 INVENTOR EL GE V LA v/vE/e Hg. 7 Mnuws TTOENEY 2,955,388Patented Oct. l1, 1960 2,955,388 SNAGGING GRINDER t Helge V. Lavner,Worcester, Mass., Iassignor to Norton Company, Worcester, Mass., acorporation of Massachusetts Filed Dec. 7, 1956, SerfNo. 627,020

4 claims. (c1. 51-35) l The invention relates to grinding machinesand'more particularly to a heavy-duty floor-type snagging Vgrinder forsurfacing steel billets and the like.

`One object of the invention is to make-a simple and thoroughlypractical heavyduty yHoor-type snagging grinder. Another object of theinvention is to provide a snagging grinder in which a longitudinallymoveable carriage serves as a support for a transversely moveablecarriage for imparting a transverse movement to the grinding wheel in ahorizontal plane;

Another object of the invention is to provide a dual driving mechanismsynchronously torotate the carriage supporting axles which arecontrolled by a -single control valve. Another object of the inventionis to provide a fluid pressure operated mechanism for imparting aswinging movement to the grinding wheel to provide a pre- Wheels 17 and22 serve to guide the carriage 10 as it is traversed longitudinally.

A suitable driving mechanism is provided for traversing the carriagelongitudinally comprising a iluid motor 25 (Fig. 1 and 3) which isconnected by a coupling 26 with a speed reducer unit 27. The speedreducer 27 may'be any of the well known commercial speed reducer units.The driven shaft of the speed reducer unit 27 is connected by thecoupling 28 with a shaft 29. The shaft 29 is provided with a fixedlymounted gear 30 (Fig. 4) which meshes with an intermediate gear 31.

The gear 31 'in turn meshes with a gear 32 which is iixedly mounted onthe axle 13. It will be readily apparent from the foregoing disclosurethat rotary motion transmitted from the uid motor 25 will be imported togive a longitudinal movement of the carriage 10.

A similar driving mechanism is provided for driving the axle 18comprising a fluid motor 35 which is connected by a coupling 36 with aspeed reducer unit 37. The driven shaft of the speed reducer unit 37 isconnected to a rotatable shaft 39 having a gear 40 xedly mountedthereon. The gear 40 meshes with an intermediate gear -41 (Fig. 4)which, in turn, meshes with a gear 42 iixedly mounted on the axle 42.The iluid motors 25 and 35 are controlled by a single control valvemechanism to be hereinafter described to control the determined high orlow grinding pressure between the grinding wheel and the work beingground while being traversed either longitudinally or transversely.Other objects will be in part obvious or in part pointed outhereinafter. In lthe accompanying drawings in which lis kshown one ofvarious possible embodiments of the mechanica-l features of thisinvention:

. Fig. l is a side elevation of the snagging grinder;

Fig. 2. .is a front elevation of the grinder;

Fig. 3 is a plan View of the grinder; Fig. 4 is a rear elevation, partlyin section, taken approximately on the line 4 4 of Fig. l;

Fig. 5 is a fragmentary horizontal sectional view, on an enlarged scale,taken approximately onthe line 5-5 of Fig. 1; K

Fig. 6 is a fragmentary vertical sectional view, on an enlarged scale,taken approximately on the lines 6 6 of Fig. 4, showing the rollersupport for the transversely movable slide; and Y Fig. 7 is a combinedhydraulic and electric diagram of the actuating mechanisms and thecontrols therefor. A heavy-duty floor-type snagging grinder has beenillustrated in the drawings comprising a longitudinally movaf blecarriage 10 which is arranged to travel longitudinally on a pair ofspaced parallel rails 11 and 12. The carriage 10 is provided with atraversely extending axle 13 which is rotatably journalled in spacedbearings 14 and 15 (Fig. 3). The axle 13 is provided with a wheel 16which rides on the rail 11,. The axle 13 is also provided with a flangedwheel 17 which is arrangedto ride upon the rail 12 so as to guide thelongitudinally movable carriage 10 during its longitudinal movement.

The carriage 10 is also provided with a rotatable axle 18 rotatablyjournalled in spaced bearings 19 and `2l) which are supported on thelongitudinally movable carriage 10.

The axle 18 is provided with a wheel 21 which Arides upon the rail 11and is also provided with a anged wheel 22 which rides upon the rail 12.It will be readily apparent 'from the foregoing disclosureV that theflanged l longitudinal movement of the carriage 10.

` A uid pressure system is provided for supplying fluid under pressureto the various mechanisms of the machine. This system comprises a uidpump 45 which is driven by an electric motor l46 (Fig. 7). The pump 45draws uid through a pipe 47 from a reservoir 48 and forces fluid underpressure through a pressure pipe 49 to the iiuid motors 25 and 35. Abalanced pressure relief valve 50 is connected in the pipe line 49 tofacilitate passing excess uid under pressure directly through a pipe 51into the reservoir 48 to facilitate maintaining a substantially constantfluid pressure throughout the system. Y

A piston type control valve 55 is provided for controlling the admissionto and exhaust of fluid from the uid motors 25 and 35. The valve 55comprises a valve stem 56 having a plurality of spaced valve pistonsformed integrally therewith to form a plurality of spaced val'vechambers 57, 58, 59, and 60. The Valve is provided with a centralpassage 61 which interconnects the valve chamber 57 with the valvechamber 59. A compression spr-ing serves normally to hold the valve stem56 in the position illustrated in Fig. 7.

A manually operable control lever 62 is provided for actuating thecontrol Valve 55. The lever 62 is pivotally supported by a stud 63carried by the upper end of a link 64. The lower end of the link 64 issupported by a stud 65 carried by the control valve 55. A stud 66connects the valve stem 56 with the control lever 62. The

-V pipe 49 is arranged to convey uid under pressure from lthe pump 45 tothe valve chamber 59 of the control valve 55. A pipe 67 is connectedbetween the control valve 55 and a throttle valve 68 which serves tocontrol the rate of exhaust of iiuid from the control valve 55 into thereservoir 48. A pipe 69 is connected between the control valve 55 andone side of each of the iluid motors 25 and v35. A pipe 70 is connectedbetween the control valve and the other side of each of the iluid motors25 and 35. VThe control valve 55 is arranged to simultaneously Vcontrolthe admission to and exhaust of iiuid from the uid motors 25 and 35. Abalance pressurerelief valve 71 is connectedbetween the pipe 70 and thepipe 69. A balance pressure relief valve 72 is similarly connectedbetween the pipe 69 and the-pipe 70. T'he balance presl. sure reliefvalves 71 and 72 are provided so that when r, J fluid under pressure tothe motors 25 and 35 is reversed fluid may readily pass between thepipes 69 and 70 respectively thereby preventing an excessive build up ofpressure in the pipe lines and motors at the time of rever-4 sal.

When it is desired to impart a longitudinally traversing movement of thecarriage the control lever 62 may jbe moved in a clockwise orcounter-clockwise direction (Fig. 7). When the control lever 62 is movedina clockwise direction (Fig. 7) the valve stem 65 is moved downwardlyagainst the compression spring. In this position of `the parts lluidunder pressure from the pipe 49 entering the valve chamber 59 passesthrough the pipe 70 A'to sta-rt both the uid motors to impart alongitudinal traversing movement to the carriage 1'0. During thismovement uid may simultaneously exhaust from the other side of the fluidmotors 25 and 35 through `the `pipe 69 into the valve chamber 58 andpass through apassage 73,through the pipe 67, through the throttle valve68 and through the exhaust pipe '51 into the reservoir 48. The rate ofmovement of vthe carriage 10 may be readily controlled by manipulationof the throttle valve 68.

When it is desired to stop the carriage 10 the control lever 62 may bereleased by the operation at which time the released compression of thespring causes an upward movement of the valve stem 56 to position thevalve 55 in a central or neutral position, as shown in Fig. 7. When Vthecontrol valve 55 is in a central or neutral position, uid under pressurefrom the pressure pipe 49 entering the valve chamber 59 may pass throughVthe central passage 60 into the valve chamber '57 and `through the pipe67 through the throttle valve 68 and exhausts through the pipe 51 intothe reservoir 48.

When it is desired to traverse the carriage 10 longitudinally in theopposite direction, the control lever 62 may be moved in acounter-clockwise direction so as to cause an upward movement of thevalve stem 56 so 'that uid under pressure entering the valve chamber 59may pass through the pipe 69 to the other side of both of the uid motors25 and 35 thereby causing the motors to rotate in opposite directionsand to traverse the carriage 10 in an opposite direction. It will beapparent 'from the foregoing disclosure that by manipulation of thecontrol lever 62 the carriage 10 may be traversed in either direction.The movement of the carriage in either direction may be stopped at anytime by releasing the control lever 62 to allow the released compressionof the spring to return the valve 55 to a central position or thelcarriage may be reversed in its direction of travel by manuallyshifting the lever 62 in the opposite direction.

The longitudinally movable carriage 10 serves as a support for atransversely movable carriage 75 (Figs. 2 and 4). The longitudinallymovable carriage 10 is provided with a pair of spaced parallel rails 76and 77. The traversely movable carriage 75 is provided with a pluralityof flanged wheels or rollers 78 and 79 which ride upon the rails 76 and77 respectively. The carriage 10 is also provided with a pair of spacedparallel depending rails 80 and 81 (Figs. 2 and 4) which serve to holdthe traversely movable carriage 75 against a lifting movement. Thetraversely movable carriage is provided with a plurality of spacedwheels or rollers 82 (Fig. 6) which ride upon the lower surface of therail 80. Either the set of rollers 78 or the set of rollers 82 may beprovided with adjustments so that lost motion may be taken up betweenthe rails 76 and 80. A similar set of rollers 83 are carried by thecarriage 75 and rolled upon the lower surface of the depending rail 81.

A hydraulically operated mechanism is provided for imparting a traversemovement to the carriage 75 comprising a pair of spaced parallelcylinders 90 and 91 (Figs. 3 and 7) which are ixedly mounted on thecarriage 75. The cylinders 90 and 91 contain the pistons 92 and 93respectively which are connected to one end of a Ypair of piston rods 94and 9S respectively.A The other'euds -of the piston rods 94 and 95 areconnected by brackets 96 and 97 respectively with a rearwardly extendingportion of the longitudinally movable carriage 10. The cylinders 90 and91 are arranged on opposite sides of the transversely movable carriage75 to facilitate the transverse traversing moving of the carriage 75.

The control valve 100 is vprovided for simultaneously controlling theadmission to and exhaust of fluid from the cylinders 90 and "91respectively. The control valve 100 is fa .piston ytype valve comprisinga valve stem 101 having'a plurality-of spaced valve pistons -formedintegrally therewith to form a plurality of spaced valve chambers 102,103 and 104. VA compression spring is provided normally "to "holdthevalve stem 101 in a central or neutral positionv as `illustrated in Fig.7.

A manually operable control lever 105 is pivotally supported by a stud106 carried by an upper end of the link 107. The lower end of the link107 is supported by a 'stud 108 carried by the valve '100. A stud 109connects the valve stem 101 with the control lever 105. A uid pressurepipe 110 is provided for conveying uid under pressure to the valvechambers 102 and 104. A pipe '112 is "connected to a ball check valve113 which is connected by a'pipe 114 with the upper-ends of thecylinders 90 and 91 respectively. Fluid passing through the pipe 114simultaneously enters a cylinder chamber 115 and a cylinder chamber 116formed in the upper ends of the cylinders 90 and 91, respectively. Apair of cylinder chambers 117 and 118 formed in the lower end of thecylinders Y90 and 91, respectively, are connected by a pipe 119with athrottle valve 120 which is in turn connected with `the valve 100. Athrottle valve 121 is connected between the -p'ipes 112 and 114. A ballcheck valve 122 lis connected between the pipes 119 and the valve 100.

When it is desired to traverse the transversely movable carriage 75, thecontrol 'lever 10S may be rocked in either -a'clockwise orcounter-clockwise direction (Fig. 7) depending upon the direction ofmovement of carriage 75 desired. fWhen it is desired to move thecarriage 75 rearwardly, that is, -in an upward direction (Fig. 3) thecontrol lever 105 is rocked in a clockwise direction to move the valvestem 101 -downwardly so that tiuid under pressure within the valvechamber '102 may pass through the pipe 112, through the ball check valve113 and the throttle valve 121 `into the pipe 114 to simultaneouslyconvey fluid under pressure into the cylinder chamber and 116respectively. yFluid under pressure entering the cylinder chambers 115and 116 causes an upward movement of the cylinders so as to cause arearward movement of the carriage 75. During this movement uid withinthe cylinder chambers 117 and 118 simultaneously exhausts through thepipe 119, through the throttle. valve into .the valve chamber 103 intoan exhaust pipe `13:1. By manipulation of the throttle valve 120, vvtherate of exhaust 'of uid from the cylinder chambers 117 Vand 118 may bereadily controlled to control the Vspeed of the rearward movement of thecarriage 75. Y lSimilarly if it is desired to cause a forward movementto the carriage 75, the control lever 105 is rocked in acounter-clockwise direction (Fig. 7) `thereby causing an upward'movement of the valve Vstem 101 Aso that Huid under pressure entering`the valve chamber 104 passes through the ball check valve 122, throughthe pipe 119 simultaneously into the 'cylinder 'chambers 117 and 118respectively thereby vmoving `the cylinders 90 and 91 respectively`together with the transversely movable carriage 75 in a forwarddirection. During this movement huid Within Athe 'cylinder chambers 115and 116 simultaneously exhausts through the pipe 114, through thethrottle valve 121, through the pipe 112 through the valve chamber1031in the valve 1'00 and exhausts through the pipe '131. 'The rate ofthe forward movement of the carriage`75 may be readily controlled bymanipulation of the throttle valve 131. Y

An independent fluid pressure system is provided for supplying fluidunder pressure to the mechanism above described and also to othermechanisms to be hereinafter described. This system compirses a tluidpump 125 (Fig. 7) which is driven by an electric motor 126. 'Ihe pump125 draws iluid through a pipe 127 from a reservoir 128 and forces fluidunder pressure through a pipe 129, through a balanced pressure reliefvalve 130 into the pressure pipe 110. The exhaust pipe 131 is connectedto the relief valve 130 to return excess iluid under pressure directlyto the reservoir 128. The relief valve 130 is preferably adjusted toopen at 300 lbs. per square inch so as to maintain an operating pressurein the lluid system of 300 lbs. persquare inch.

'Ihe transversely movable slide or carriage 75 serves as a support for apivotally mounted frame 140 which is provided with horizontallyextending portions 141 and 142. The portion 141 is provided with atrunnion 143 which is supported in a bearing 144 mounted in an upwardlyextending bracket 145 on the carriage 75. The horizontally extendingportion 142 of the frame 140 is provided with a trunnion 146 which isjournalled in a bearing 147 supported by an upwardly extending bracket148 lixedly mounted on'the carriage 75. The frame 140 is provided withan opening 149 to facilitate passing a driving mechanism for a grindingWheel to be hereinafter described.

The frame 140 is provided with a horizontally extending arm 150 (Figs. land 3). A hydraulically operated mechanism is provided to facilitaterocking the frame 140 about the axis of the trunnion 143-146 as a pivot.This mechanism comprises a cylinder 155 which is pivotally supported bya bearing 154 mounted on the transversely movable carriage 75 (Fig. 1).The cylinder 155 contains a slidably mounted piston 156 which isconnected to the lower end of a piston rod 157. The upper end of thepiston rod 157 is connected by the stud 158 carried by a bracket 159formed integral with the arm 150 of the frame 140. It will be readilyapparent from the foregoing disclosure that movement of the piston 156within the cylinder 155 will impart a rocking motion to the arm 150 andthe frame 140 to control the feeding movement of a grinding wheel to behereinafter described.

In order to provide a controlled movement of the piston 156, it isdesirable to rely upon the differential effective area of the piston156. The effective 4area of the upper surface of the piston is less thanthe effective area of the lower surface thereof due to the piston rod157. Fluid under pressure from the pipe 110 is con tinuously passedthrough the check valve 160 and -a throttle valve 166, through a pipe161 into a cylinder chamber 162 to exert a downward thrust on the piston156 tending to` rock the frame 140 in a counter-clockwise direction(Fig. 1). The throttle valve 166 controls the rate of exhaust of iluidfrom -the cylinder chamber 162 against the pressure in the pipe 110 whenlluid under pressure is passed into the cylinder chamber 164. Due to thegreater area of the under side of the piston 156, a controlled swingingmovement is imparted to the frame 140 to produce the -desired grindingpressure.

A control valve 170 is provided for controlling the admission to andexhaust of uid from the cylinder chamber 164. The valve 170 is a pistontype valve having a valve stem 171 formed with a plurality of spacedpisf tons to form a plurality of spaced valve chambers 172, 173 and 174.A manually operable control lever 175 is pivotally supported by a stud176 to the upper end of a llink 177. The lowerend of the link 177 isconnected by a stud 178 with the valve 170. A stud 179 connects thecontrol lever 175 with the valve stem 171. A spring pressed detent 180is arranged to engage one of a plurality of spaced grooves 181, 182,-and 183 to maintain the Valve stem 171 in -a predetermined position. Apipe 185 is connected between the valve 170 and a pressure reducingvalve 186 which contains a vertically arranged sldable valve member 187.The valve 186 is connected by a pipe 188 with a ball check valve 189 anda throttle valve 190 with the pipe 163 leading to the cylinder chamber164. A ball check valve191 (Fig. 7) is connected between the pipe 188and the pipe 185.

The slidably mounted valve member 187 of the pressure reducing valve 186is provided with ya central passage 192 Vwhich is arranged so that whenthe sldable valve member 187 moves upwardly iluid may pass through thecentral passage 192 and through a vent pipe 193 to a rotary controlvalve 194.V The control valve 194 is operatively connected in a mannerto be hereinafter described to pass lluid from the venting pipe 193either to an adjustable relief valve 196 or to an adjustable reliefvalve 197 which are adjusted to operate at different pressures so as tofacilitate controlling the pressure conveyed to the cylinder chamber164.

The valve 194 contains a valve rotor 198 which is actuated by a manually`operable control lever 199. In the position of the valve 194 (Fig. 7)fluid passing through the venting pipe 193 enters a valve chamber 200 inthe valve 194 and passes through a pipe 201 to the relief valve 196which allows excess fluid under pressure to pass through the exhaustpipe 131 into the reservoir 128 thereby reducing the lluid pressurepassed tol the cylinder chamber 194.

If desired the control lever 199 may be swung into position 199e to turnthe valve rotor 198 so that fluid under A pressure entering the valvechamber 200 may pass through a passage 202 in the valve rotor'198 into avalve chamber 203 and through a pipe 204 to the relief valve 197 so thatexcess iluid may be passed through the re' lief valve 197 into theexhaust pipe 131 which exhausts into the reservoir 128.

The pressure reducing valve 186 is provided with a pilot control piston205. The pilot control piston 205 is spring pressed `and adjustable sothat iluid passing through the central passage 192 into the pipe 193 maymove the piston 205 toward the right (Fig. 7) to allow a variabileamount of lluid to pass through a drain pipe 206 into the exhaust pipe131. The pilot control piston 205 is preferably adjusted to open atpressure in excess of the setting of relief valve to allow excess fluidto exhaust through pipe 131 into the reservoir 128.

When it is desired to impart a clockwise feeding movement to the frame140, the control lever is'rocked in a counter-clockwise direction untilthe spring pressed detent engages the groove 183. In this position ofthe valve 170 lluid from the pipe 110 passes through the valve chamber174, through the pipe 185, through the pressure reducing valve 186,through the pipe 188, through the ball check Valve 189 and the throttlevalve 190, through the pipe 163 into the valve chamber 164 to cause anupward movement of the piston 156 at a predetermined controlled rate.During this feeding movement excess iluid under pressure within the pipe188 causes an upward movement of the valve member 187 (Fig. 7) whichserves to allow fluid under pressure to pass through the pipe 193 to-the rot-ary control valve 194 and through either the relief valve 196or the relief valve 197 into the exhaust pipe 131.

The relief Valves 196 and 197 are adjustable to faci-litate varying thegrinding pressure of the grinding wheel 228 and the work piece 285. Thevalve 196 may be set to open at 75 lbs. per square inch and the valve197 may be set to open at 200 lbs. per square inch to facilitateobtaining either a low or a high grinding pressure. lAt the same timethe pilot control piston 205 may be moved toward the right to allow aportion of the excess fluid to pass through the venting pipe 206 intothe exhaust pipe 131. It will be readily apparent from the foregoingdisclosure that by applying a predetermined pressure toward the upperface of the piston 156 and applying a controlled pressure to the lowersurface of the piston 156` having a greater piston area will cause acontrolled upward movement of the piston 156 (Fig. 7) thereby impartingacontrolled feeding movement to the frame 140 in aclockwise direction(Fig. 1).

When it `is desiredto rock the frame 140 in a countercloekwise direction(Fig. l), the control lever 175 may be moved in a clockwise directionuntil the detent 180 engages lthe groove 181. In this position of thevalve fluid under pressure from the pipe 110 is cut oi from the valve170 and 'iiuid from lthe cylinder chamber 164 may exhaust through thepipe 163 through the throttle valve 190, through the ball check valve191, through the pipe 185, 'through the valve chamber 173 into theexhaust pipe 131 which exhausts into the reservoir 128. By manipulationof the pressure reducing valve 186 and the relief valves 196 and 197 aprecise control of fluid under pressure entering the cylinder chamber164 may be obtained.

The 'frame 140 serves as a support for a grinding unit 220. The grindingunit 220 comprises a cylindrically shaped support 221 which isjournalled in spaced bearings 222 and 223 which are iixedly mountedwithin an aperture formed in the frame 140. The grinding unit furthercomprises a frame 224 which serves as a combined support for a grindingwheel 'and as a wheel guard. The frame 224 (Fig. 5) supports a lixedlymounted non-rotatable spindle 225. The spindle 225 supports a pair ofspaced roller bearings 226 which in turn support a rotatable wheelsleeve 227 upon which a grinding wheel 228 is mounted. The grinding unit220 is arranged to rock about the axis of the cylindrical member 221. Inorder to perform a heavy duty snagging operation, the longirtudinallymovable carriage 10, the transversely movable carriage 75, the pivotallymounted frame 140 together with lassociated parts are massive instructure so that a large diameter grinding wheel, such as, ya 36diameter grinding wheel 228 driven by a 75 H.P. driving motor may beemployed to facilitate rapid stock removal from the billet or work piecebeing ground.

A driving mechanism is provided for the grinding wheel 228 comprising`an open-ended box-like frame 230 which is xedly keyed onto the lefthand end of the cylindrical member 221 (Fig. 5). The opposite side oftheboxlike frame 230 is provided with a ixedly mounted trunnion 231 "whichis supported in a bearing 232 carried by a downwardly projecting bracket233 which is fastened Ito the left hand end of the arm 150 of the frame148. An adjusting screw 234 is provided to facilitate taking up the endthrust of the grinder unit 220 in `a direction toward the left (Fig. 5).

The box-like frame 230 supports a wheel driving motor 235 haiving a cogpulley 236 which is connected by a cog driving belt 237 with a cogpulley 238 which is keyed onto the upper end of a rotatable shaft 239.The Ishaft 239 is iournalled in a pair of spaced bearings 240 and 241which `are supported in a bracket 242 tixedly mounted on the boxalikeframe 230. The yaxis of the shaft 239 is preferably in axial alignmentwith the trunnions 143 and 146 of the frame 140 in order to facilitatethe swinging movement of the frame 140 about the axis of the trunnions.

A cog pulley 243 is keyed onto the lower end of the shaft 239 (Fig. 5The pulley 243 is connected by a cog driving ybelt 244 with a cog pulley245 which is carried by the wheel sleeve 227. A Wheel guide cover 246encloses the open side of the frame 224. It will be readily apparentfrom the foregoing disclosure that the motor 235 will transmit power torotate the grinding wheel 228 during a swinging or feeding movement ofthe frame 140.

It is desirable to rock the grinding wheel in a vertical plane passingthrough its axis. This rocking movement is obtained by a hydraulicallyoperated mechanism comprising a pair of cylinders 250 and 251, the upperends of which are connected by studs 252 and 253, respectively, with abracket 254 which is ixedly mounted relative .to the .frame .140. The.cylinders 25.0 and A251 contain slidably mounted pistons 255 and 256respectively. The pistons 255 and 256 are connected to the upper `endsof a vpair of piston rods 257 and 258 respectively. The lower ends ofthe piston -rods y257 and 258 are connected by a pair of studs 259 and260 respectively with a pair of brackets 261 and 262 which are fixcdlymounted on `the rear surface of the box like frame 230.

A control valve 265 is provided for controlling the admission to andexhaust of uid from the'cylinders 250 and 251 respectively to obtain thedesired rocking movement of the wheel supporting frame 224. The controlvalve 265 is a piston -type valve having `a valve stern 266 which isactuated Vby a control lever 267. The control lever is pivotallysupported by a stud 268 on the upper end of a link 269. The lower end ofthe link 269 is connected by a stud 270 carried by the valve 265.

The valve stem 266 is provided with a plurality of spaced valve pistonsvforming a plurality of spaced valve chambers 271, 272, and 273. Acompression spring 274 serves normally to maintain the valve 265 in acentral or neutral position, as indicated in Fig. 7. A pipe 275 connectsthe valve 265 with a lower cylinder chamber 276 in the cylinder 250 andan upper cylinder chamber 277 in the cylinder .251. A pipe 278 connectsthe valve 265 with a lower cylinder chamber 279 in the cylinder 251 andan upper cylinder chamber 280 in the cylinder 250.

The valve 265 is provided with a passage 281 which receives fluid underpressure from the pressure pipe 110. With the valve 265 in a central orneutral position, fluid under pressure is conveyed by the passage 281into the valve chambers 271 and 273. When it is desired to impart aclockwise rocking motion to the frame (Fig. 7), the control lever 267 isrocked in a clockwise direction to cause a downward movement of thevalve stem 266 so that tluid under pressure entering the valve chamber271 passes through the pipe 275 simultaneously into the cylinderchambers 276 and 277. During this rocking movement of the frame 140iluid within the cylinder chambers 279 and 280 exhausts through the pipe278, through the valve chamber 272 into the exhaust pipe 131 whichexhausts into the reservoir 128.

Similarly when a rocking motion in a counter-clockwise direction of theframe 140 is desired, the control lever 267 is rocked in acounter-clockwise direction thereby causing an upward movement of thevalve stem 266 so that iluid under pressure from the valve chamber 273passes through the pipe 278 into the cylinder chambers 279 and 280 toimpart a counter-clockwise swinging of the box-like frame 230 and theframe 140. During this movement fluid may exhaust from the cylinderchambers 276 and 277, through the pipe 275 into the valve chamber 272and pass through the exhaust pipe 231 into the reservoir 128.

A work piece 285, such as a billet or slab of steel to be snagged may beplaced on a work supporting base 286. The grinding wheel 228 may then befed downwardly by a swinging movement of the frame 140 into operativeengagement with the surface to be ground. The carriage 10 may betraversed longitudinally by imparting a longitudinal traversing movementto the carriage 10. The grinding wheel 228 may be moved transversely topresent the wheel to a different portion of the work piece being snaggedby imparting a traverse movement to the carriage 75. Due to the opposedroller support for the transversely movable carriage 75, any desiredgrinding pressure may be imparted to the grinding wheel 228. If desiredthe grinding unit 220 may be rocked about a horizontal axis so as totilt -the grinding wheel in either direction as shown in Fig. 2.

In Fig. l, the arm of the frame 140 has been illustrated in broken lineposition 150a when the `frame 140 is swung in a clockwise direction toswing the grinding wheel 228 `in-to its extreme lower position 228a. Arm150 has also been shown in broken line position 150b when lthe frame 140is swung in a counter-clockwise direction to swing the grinding Wheel228 into its extreme upper position 228b. The arm 150 has also beenshown in broken line position 150C when the slide 75 is moved toward theleft (Fig. 1) to position the grinding wheel 228 in broken line position228e.

. `In Fig. 2, the broken positions 228d and 228e of the grinding wheel228 illustrate extreme positions of the grinding Wheel 228 when thegrinding wheel unit 220 is swung within theV bearings 221-222 (Fig. 5).v

An operators seat 290 (Figs. 1 and 2) is provided at a control station291 on the transversely movable slide 75. The control levers 62, 105,175, 199 and 267 for actuating the control valves 55, 100, 170, 194 and265, respectively', are positioned wi-thin easy reach of the operator. Y

The operation of the improved snagging grinder will be readily apparentfrom the foregoing disclosure. After a work piece 285 has beenpositioned on the work support 286, the wheel driving motor 235 isstarted by closing a switch 287. The pump driving motor 46 is started byclosing the switch SW2. The pump driving motor 1264is started by closingIthe switch SW1.

By manipulation of the control lever 175, the valve 170 may be actuatedto swing the frame 140v in a clockwise direction (Fig. 1) to feed thegrinding wheel 22S into grinding engagement with the work piece 285 at adesired and predetermined pressure. The grinding pressure may be variedby manipulation of the valve 194 and by adjustment of the relief valves196 and 197. The carriage 10 may then be traversed longitudinally byactuation of the control lever 62 which in turn actuates the controlvalve 55 to start the iluid motors 25 and 35 in either direction. Thedirection of movement of the carriage being determined by the directionof movement of the control lever 62. At the end of a longitudinal strokeof the grinding wheel 228, the carriage 75 may be traversed transverselyby lactuation of the -control lever 105 to present a new portion of thework surface to be ground during the next longitudinal traverse of thecarriage 10. `If desired the surface of the work piece being snagged orground may be ground by successive longitudinal movement of the carriage10 combined with a transverse movement of the carriage 75 at the ends ofthe longitudinal stroke of the carriage 10.

If desired, a transverse movement of the carriage 75 controlled by thecontrol lever 105 may be utilized to traverse the grinding wheel 228transversely across the' work piece 285. After the grinding wheel hasground the surface to the desired extent, the longitudinal moveablegrinding wheel carriage may be moved longitudinally to present thegrindin-g wheel to an adjacent portion of the surface. This sequence maybe continued until the entire surface has been ground to the desired andpredetermined extent. After a predetermined area has been ground at oneend of the work piece in a manner above described, the carriage 10 maybe traversed longitudinal-ly to present the grinding wheel to the otherend portion of the work piece to be ground. A similar portion of theface of the work piece may be ground to the desired extent by atransverse movement of the carriage 75. After an area at each end of thework piece has been ground to the desired extent by a transversemovement of the carriage 75, the longitudinally movable carriage 10 maybe traversed longitudinally to grind the area between -the two endportions. Between longitudinal strokes by the carriage l()` the carriage75 may be advanced transversely so as to present the grinding wheel to|a new portion of the work piece on each successive longitudinal stroke.

In both methods of operation, that is, by grinding with fa longitudinalstroke or grinding by a transverse stroke of the wheel, the wheel axism-ay be mounted parallel to the plane of the work surface or may betilted into either the position 228e or 228d when desired. If it isdesired to change the pressure of the grinding wheel against the l0 workpiece, the control valve 194 may be actuated to render -the relief valve196 or the relief valve 197 operative.

It will therefore be seen that there has been provided by this inventionapparatus in which the various objects hereinafter set forth togetherwtih many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges might be made in the embodiments above set forth, it -is to beunderstood that all matter herein-before set forth or shown in theaccompanying drawings is-to be interpreted as illustrative and not in allimiting sense.

I claim:

1. A snagging grinder comprising a traversable longitudinal carriage, ailuid motor to traverse said carriage, a transversely movable slide onsaid carriage, a iiuid motor interposed between the carriage and theslide to move said slide transversely of the carriage, a pivotallymounted swing frame .supported on said slide, spaced axially alignedhorizontally arranged trunnions on said frame, spaced bearings on saidslide for said trunnions` having their common axis arranged parallel tothe direction of movement of the longitudinal carriage, a fluid motor toswing said frame relative to said slide, an elongated grinding unit onsaid frame including a support for said unit projecting through androtatably mounted on said frame, ythe axis of said support beingrotatable about the axis of said trunnions in a vertical plane parallelto .the path of movement of said slide, a grinding wheel rotatablymounted on one end of said unit, a box-like frame iixedly mounted on theother end of said unit, an electric motor adjustably supported on saidboxlike frame, a trunnion `iixedly mounted on said box-like frame inaxial alignment with the said rotatable Support, -a bearing on saidswing frame to support said trunnion, a rota-table shaft, spacedbearings supported on said grinding unit for supporting said shaft in acommon plane with the spaced trunnions on sia-id swing fname, beltdriving connections between said motor and said shaft, and belt drivingconnections between said shaft and said grinding wheel to facilitatedriving .the grinding wheel in any position of the swing frame orgrinding unit without disturbing the belt driving connections betweenthe motor and the grinding wheel.

2. A snagging grinder comprising a traversable longitudinal carriage, afluid motor to traverse said carriage, a

transversely .movable slide on said carriage, a fluid motor interposedbetween the carriage and the slide to move said slide transversely ofthe carriage, a pivotally mounted swing frame supported on said slide,spaced axially aligned horizontally arranged trunnions on said frame,spaced bearings on said slide for said trunnions having their commonaxis arranged parallel to the direct-ion of movement of the longitudinalcarriage, a fluid motor to swing said frame relative to said slide, anelongated support for a grinding wheel projecting through and mountedrotatably on said frame, the axis of rotation of said support beingrotatable about the axis of said trunnions in a vertical plane parallelto the path of movement of said slide, a grinding Wheel rotatablyjournalled in bearings mounted on one end of said support, Ia box-likeframe fixedly mounted on the other end of s-aid support, an electricmotor supported within said box-like frame, a trunnion fixedly mountedon said boxlike frame in axial alignment with said rotatable support, lalbearing on said swing frame to support said trlmnion, a rotatabledriven shaft, spaced bearings supported on said box-like frame forsupporting said shaft for angular ldisplacement about the axis of saidsupport in a plane intersecting the spaced ltrunnions on said swingframe, bel-t driving connections between said motor and said shaft, andbelt driving connections between said shaft and said grinding wheel tofacilitate driving the grinding wheel in any position of the swing frame9i' 1 1 grinding unit without imparting a. ltwist to saidy drivingbelts.

3. `In a snagging grinder, as claimed in claim 1, in combination withthe parts and features therein specified in which the `uid motor forswinging the grinder frame relative to the transverse slide comprises apiston and cylinder, operative connections between the frame andtransverse slide, said piston having differential piston areas, meansfor applying pressure direct from a source to the upper end of saidcylinder to exert a downward pressure on the smaller piston area, andmeans including a manually operable control valve operatively connectedto apply a lower pressure to the greater piston area on the under sideof said piston so as to impart a controlled swinging movement to :theframe and grinder unit lto obtain the desired grinding pressure.

v4. In a snagging grinder as claimed in claim 3, in combination with theparts and features therein specified of means including a pressureregulating valve to pass fluid under pressure to the lower end of saidcylinder, means including a pair of independent adjustable reliefva-lves one of which -is `set lfor a low grinding pressurel and theother set for Ia high grinding pressure, said relief valves -beingarranged to exhaust excess uid under pressure from the pressureregulating valve, and means including a manually operable valve torender either of said relief valves operative to facilitate obtainingeither a controlled high or low pressure between the grinding Wheel andthe work piece being ground.

Hamilton May 25, 1948 Muehling June 19, 1956

